<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
<title>Windows操作系统的版本</title>
</head>
<script type="text/javascript">
	function validB(){ 
	    var version = navigator.platform;
	    document.write("操作系统："+version+"<br>");
}
</script>
<body>
	<form>
     <input type="button" value="查看操作系统"  onclick="validB()" >
  </form>
</body>
</html>